In this program project we present a novel strategy for the identification of genes important for psychiatric disorders. The studies are aimed at normal and pathological expressions of anxiety in humans, and focus specifically on learned and innate fear in mice. Because fear is a universal affect conserved throughout phylogeny, it is possible to model fear in mice - an organism that is suitable for both physiological and genetic analysis. Fear conditioning is a measure of an organism's basic ability to learn about new dangerous or threatening stimuli or environments, and to respond appropriately. The study of fear conditioning offers two very significant advantages for molecular genetic analysis: the behavioral paradigms can be closely mimicked in human subjects, and the neurocircuitry, and associated information processing systems that underlie these behaviors, are relatively well understood, and highly conserved among vertebrates. Since, in their most general sense, anxiety disorders represent a malfunction in the neural mechanisms that detect danger and mobilize adaptive responses to that danger, we propose that a subset of genes that harbor genetic determinants for learned or innate forms of fear will also harbor susceptibility alleles for human anxiety disorders. Thus, we propose a translational study of fear and anxiety that combines direct molecular genetic study of learned and innate forms of fear in mice with genetic analysis of anxiety related behaviors, traits, and disorders in humans. The Program Project consists of five independent Projects and a Training Component. 1. Genetic and Behavioral Models of Fear States in Mice- 1A. Learned Fear (Kandel) 2A. Innate Fear (Hen). 2.Translation from Mouse to Human Fear and Anxiety: Genetic and Genomic Approaches (Gilliam). 3. Clinical Studies of Human Fear and Anxiety (Fyer). 4. Clinical Studies of Human Anxiety Disorders (Weissman).